Phospha-Michael addition of biphenylphosphine oxide to chalcones and α,β-unsaturated esters using the organocatalyst 1,1-diaminobenzalazine

Abstract

The phospha-Michael addition (PMA) to many Michael acceptors like nitro-olefins, cyclic enones is well known. Chalcones and α,β-unsaturated esters are rarely employed in PMA reaction. In this article, we report the PMA of biphenylphosphine oxide to chalcone and α,β-unsaturated esters using the newly identified organocatalyst 1,1-diaminobenzalazine. The reaction has wide substrate scope, and the products were formed with very good yields. This work establishes the versatility of the organocatalyst 1,1-diaminobenzalazine in producing substituted 3-(diphenylphosphoryl)-1,3-diphenylpropan-1-ones.